Change description font to match header
Change description font to match header

# What
Update the description font size to 19 to match the size of the header

# Why
Styling updates to make the description more visible

https://trello.com/c/mNuWA1DC/689-change-description-font-to-match-header

alphagov/collections,alphagov/collections,alphagov/collections,alphagov/collections